Lathe-center



Patented. Dec. 20, 192k.

E. H. DAVIS AND D. D. BAKED.

LLUSL UNITED stares PATENT oFFIc-E.

aunar. H. Davis aan RAYMOND n. nanna, or arriendo, ILLINOIS.

nanna-Gmane. I

.application filed June 14,

To all whom it may concern.' Y

Be it known that we, EUELL H. DAVIS and RAYMOND D. BAKER. citizens of the United- States of America, and residents of Chicago, in the county of Cook, State of Illinois, have invented certain new and useful Improvements in Lathe-Centers, of which` the following is a specification.

This invention relates to that class of lathe centers in which the work engaging spindle is revoluble in its carrying stem, which in turn has a stationary lit in the arbor of the tail stock or like member of the lathe.

The object of the present improvement is to provide a simple and eective structural formation and combination of parts, whereby the work engaging spindle is revolubly mounted in its carrying stem in a manner adapted to reduce frictional resistance to a minimum to take up wear due to continued use, and by means of which lateral as well as end movement of the spindle is prevented in an accurate and effective manner, all as will hereinafter more fully appear.

In the .accompanying drawings Figure 1l, is a longitudinal sectional elevation of a lathe center embodying the preferred form of the present invention.

Fig. 2 is a transverse section on line 2-2 Fig. 1.

ike reference numerals indicate like parts in both views.

Referring to the drawing, l designates the carrying stem or body, the rear portion 2 of which is of the usual tapering form adapting the same to fit the tail stock of a lathe or like machine. The forward end of the stem or body 1 is externally screwthreaded for the adjustable attachment of the hereinafter described ball race cup or sleeve, 4and to such end is also formed with an axial bore or cavity 3 adapted to contain .the rear shank of the workengaging spindle Specication of Letters Patent. Pmtlnttll 20,`

1920. serial no. 388,908.

end wallv of the axialy bore 3 and having bearing'in alined recesses in the parts.` The ball 8 is vadapted to receive `the Aentire end thrust of the work engaging spindle t in actual use, and in the preferred yconstruction shown in thev drawing full clearance space is allowed between the bore 3 and the shank 6 aforesaid.

9 designates the ball race cap or sleeve heretofore referred to, of a cylindrical shell form and provided at its forward end with an inturned annular flange 10 formed as a ball race and adapted in conjunction with a series of balls ll or the like, and the ball bearing cone 7 aforesaid, to constitute the bearing between the parts which bear all the lateral thrust on the lathe center in actual use. The rear portion of the cap or sleeve 9 is internally screw-threaded and fits the screw-threaded forward end of the carrying stem or body l, and by a turning adjustment thereon is adapted to move the series of balls ll upon the bearing cone 7 to attain the required close bearing tit of the parts. y

l2 designates a set screw passing through the cap or sleeve 9 for the purpose of lockin the same in place after an adjustment.

laving thus full described our said invention what we c aim as new and desire to secure by Letters Patent, is

l. A lathe center comprising, a carrying stem formed with an axial bore, a work engaging spindle having a shank portion extending into said bore and a ball bearing portion intermediate its length and of a frustoconical form the expansion of which is rearward, a ball race member associated with the forward end of the carrying stem, a series of interposed rolling members, and means for adjusting said ball race member in relation to said carrying stem, substantially as set forth.

2. A lathe center comprising, a carrying stem formed with an axial bore, a -work engaging spindle having a shank portion extending into said bore and a ball bearing portion intermediate its length and of a frustoconical form the expansion of which is rear ward, a ball race member associated with the forward end --of the carrying stem, a

engaging spindle and the opposed wall of the bore of the carrying stem and bearing in opposed recesses in said parts, substantially as set forth.

3. A lathe center comprising, a carrying stem formed with an axial bore, a work engaging spindle having va shank portion extending into said bore and a ball bearing portion lntermediate its length and of a frustoconical form the expansion of which is rearward. a sleeve screwing upon the forward end of the carrying stem and provided at its forward end with an annular ball race flange, and a series of balls interposed between said ball race flange and the bearing cone aforesaid, substantially as set forth. 4. A lathe center comprising, a earryin stem formed with an axial bore, a wor engaging spindle having a shank portion extending into said bore and a ball bearing the bore of the carrying stem and bearing in opposed recesses in said parts, substantially as set forth.

Signed at Chicago,u1llinois, this 12th day` of June, 1920.

EUELL H. DAVIS. RAYMOND D. BAKER. 

